. Elements of comparative anatomy. Anatomy, Comparative. 209. The three divisions of the enteric tube are distinctly marked off in the Protra- Fig. 137. Digestive organs of a Spider, oe (Esophagus. c Supraoesophageal ganglion (Cerebrum). v Stomach. v' Its lateral processes. v" Appendages directed up- wards, i Mid-gut. r Cloacal widened end of the enteron. hh Openings from the liver into the enteron. e Urinary- canals (after Dnges). into a larger The narrow cheata; the mid-gut, which is distinguished by its width, forms the largest part of it. The enteric tube of the Arachnida is divided n
. Elements of comparative anatomy. Anatomy, Comparative. 209. The three divisions of the enteric tube are distinctly marked off in the Protra- Fig. 137. Digestive organs of a Spider, oe (Esophagus. c Supraoesophageal ganglion (Cerebrum). v Stomach. v' Its lateral processes. v" Appendages directed up- wards, i Mid-gut. r Cloacal widened end of the enteron. hh Openings from the liver into the enteron. e Urinary- canals (after Dnges). into a larger The narrow cheata; the mid-gut, which is distinguished by its width, forms the largest part of it. The enteric tube of the Arachnida is divided number of segments, except in the degenerate forms fore-gut (Fig. 137, oe) leads into a mid-gut, which is generally elongated, and has its more anterior portion (v) frayed out into lateral caecal sacs. These are absent in the Phrynida and Scorpionea. In the Aranea there are five pairs of them (v!), which extend to the base of the legs and palps. In the Galeodea four pairs, the last two of which are bifurcated, extend into the appendages (feet, claws, and palps); in the Pycnogo- nida these caeca extend almost to the end of the appendages (Fig. 138, h). The presence of these parts greatly increases the internal cavity of the stomach. In the Acarina these caecal sacs are confined to the body ; there are generally eight of them, but any diminution in number is. Fig. 133. Digestive organs of Ammothoe pycnogonoides. a Stomach, b Ca?ca (after Quatre. fagos).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Gegenbaur, C. (Carl), 1826-1903; Bell, F. J. (Francis Jeffrey), 1855-1924; Lankester, E. Ray (Edwin Ray), Sir, 1847-1929. London, Macmillan and Co.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectanatomycomparative
